Mugs having covers for maintaining a temperature of a beverage are well know and are available in wide variety of models and designs. Such mugs typically have a friction fit or threaded closure for inhibiting fluid spilling from the mug when the mug is jostled or tipped. Such mugs have a joint between the sidewall of the mug and a sidewall of the lid. The lid typically comprises an upstanding rim that surrounds a well into which the beverage enters through one or more fluid passages as the beverage is consumed.
A long standing problem with such mugs is providing a secure seal between the lid and the mug. A great deal of inventive ingenuity has been invested in designing fluid seals and precession molds for ensuring that leakage does not occur between the lid and the mug because such leakage inevitably dribbles the beverage onto clothing of the user. However, it is well know that even the best of such mugs will leak if the lid is worn or improperly secured. Besides, even a good seal may seep fluid due to surface tension and capillary action if the lid is secured when the joint is not dry.
This problem has been eliminated by mugs having solid outer sidewalls with recessed lids, such as described in U.S. Pat. No. 4,582,218 which issued on Apr. 15, 1986 to Ross; U.S. Pat. No. 5,249,703 which issued Oct. 5, 1993 to Karp; and U.S. Pat. No. 5,217,141 which issued on Jun. 8, 1983 to Ross. Although the mugs described by Ross and Karp eliminate leakage between the lid and the mug, they have the disadvantage of a recessed lid that may be soiled by the beverage consumed. Consequently, handling the lid may be messy and potentially unhygienic.
This problem is partially addressed by U.S. Design Pat. 396,381 which issued on Jul. 28, 1998 to Chung Young. However, a disadvantage of Young's design is that a fluid-tight seal is required between the lid and the inner side of the mug to ensure that fluid does not dribble onto the user when a beverage is being consumed.
There therefore exists a need for a travel mug that provides improved security against leaks or drips when a beverage is consumed from the mug.